Advanced Engine Diagnostics help

[Wozza]

check your stock (non mace) memcals against this site
http://www.geocities.ws/memcals/vrcals.html
check that its of a correct date and model, there were changes throughout the series..

next check all the pins/sockets on the harness and pcm relating to the errors your getting..use a tiny file and contact cleaner to clean them up..make sure battery is discoed

 

[Wozza]

Wozza as for replacing the entire engine harness is not a goer unless I can get lucky enough to find one, complete ones are extremely rare.

Ive seen em on slumtree for around 90$ but yeah they can be pricey on the bay and from wreckers....

 

[losh1971]

check your stock (non mace) memcals against this site
http://www.geocities.ws/memcals/vrcals.html
check that its of a correct date and model, there were changes throughout the series..

next check all the pins/sockets on the harness and pcm relating to the errors your getting..use a tiny file and contact cleaner to clean them up..make sure battery is discoed

I don't think there is any issues with the memcal, especially AFAIK the changes related to trans only. The Mace memcal is the correct year and is not giving me any codes related to trans. I probably need the valve body reamed and new larger valve fitted but that is like most VR autos out there will have this prob, which will generally cause TCC error codes, that I am not currently getting. I don't see it causing a loss of O2 signal to the PCM, and or lean codes if they return after a couple of 100 more km's.

I'm leaning towards a wiring issue or a failed sensor. Just not sure what to try in the way of wiring or if I just need to bite the bullet and spend the $55 a buy a new sensor and see if that fixes the issue. I'm reluctant to buy another sensor but if I have too I will. Just a bummer I need to keep throwing parts at it until I figure out the actual issue.

Initially it would appear that a change in PCM has improved things but need more time and km's to confirm. Both plugs on the PCM are clean. I'm not sure where else it plugs into for me to check.

I don't know much about heater circuits but I would think that a no signal issue would probably be a ground problem rather than a heater wire issue??

 

[losh1971]

So I have just ordered a new sensor to see if that fixes the issue. Question I used black RTV on the rear side of the cat on the flange, when I replaced the exhaust a few months before I fitted the new O2. Could this cause the sensor to fail? If yes I will get some sensor safe gear and clean up the gaskets and reseal them with the blue RTV.

 

[delcowizzid]

Any sealant that smells like salt and vineger chips anywhere in between the throttle and o2 sensor can badly contaminate the sensors fast

 

[losh1971]

Probably ok then since the sensor is in front of the cat and the black gear is after cat? Should I clean it up and use the blue gear anyway or is that not necessary?

 

[delcowizzid]

If you have the time I would cause the whole system will full with vapors after shutoff I don't know how long it takes to offgas all the bad stuff or if it ever does so I spose do it for piece of mind

 

[losh1971]

Good point. I will get some more blue sensor safe gear and clean off the old black gear just go from there. See what happens re these CEL's and errors once I fit a new sensor.

 

[gtrboyy]

Seeing that ute has been messed around with have you checked broken earth wire in harness?

Earth wires usually bridged together in engine harness...seen them broken or not conected on v8's a few times,v6 harness might do it too.

 

[losh1971]

Yeah I'd like to have a look at them but I don't know where the loom grounds are located. I have less than ideal body and engine grounds from the battery but really need to wait until next pay to buy some cable and solder lugs. I also need to wait until I head home next as I need a few tools that I didn't bring in to Town to clean up the main ground point on the body.
At the moment I am working through the process of elimination, seems the only thing I can do....
Replacement PCM didn't fix it, neither did replacing the signal cable. Next week a new sensor will go in. If that doesn't fix it then I am back to wiring and am not sure which wires to replace next. I hope it doesn't come down to employing an auto electrician, but I may have no choice; unless I just live with it, which I don't want to do either. If the new O2 doesn't fix it, it may have to wait until late this year. Need to stop spending money on this old ute for a bit. I have had to put off the trans repairs and upgrades a couple of months because of chasing my tail trying to fix something that is more annoying that actually problematic...